Access USGS The National Map for elevation data (DEMs), geologic maps, topographic maps, hydrography, imagery, and geospatial products via the TNM Access API. Use when the user asks about elevation near a well site, DEM download, USGS topographic maps, geologic maps, surface slope for facility siting, lidar data, 3DEP elevation, National Elevation Dataset, ortho imagery, hydrography near a well pad, watershed boundaries, NHD, or USGS geospatial products. Trigger phrases: "elevation data near well", "download DEM for WV", "topo map Monongalia County", "geologic map Appalachian Basin", "lidar data", "terrain analysis", "slope for pad siting", "USGS topo map", "3DEP elevation", "NHD hydrography", "watershed boundaries", "ortho imagery". Covers NGMDB MapView and USGS SGMC. Produces download links and geospatial product metadata.
Accesses USGS geospatial data products through The National Map API -- elevation (3DEP/NED), topographic maps, hydrography (NHD), imagery (NAIP), and related datasets. Also covers USGS geologic map services (SGMC, NGMDB).
None required. All TNM services are publicly accessible.
# No API key needed -- USGS TNM services are open access
| Source | Type | URL |
|---|---|---|
| TNM Access API | REST API (JSON) | https://tnmaccess.nationalmap.gov/api/v1/ |
| 3DEP Elevation Viewer | Web map |
| https://apps.nationalmap.gov/3depdem/ |
| NGMDB MapView | Web map (geologic maps) | https://ngmdb.usgs.gov/mapview/ |
| SGMC (State Geologic Map Compilation) | WMS service | https://mrdata.usgs.gov/services/sgmc |
| National Map Download | Web download manager | https://apps.nationalmap.gov/downloader/ |
| USGS Lidar Explorer | Web map (point cloud data) | https://apps.nationalmap.gov/lidar-explorer/ |
Base URL: https://tnmaccess.nationalmap.gov/api/v1/
Endpoints:
| Endpoint | Description |
|---|---|
/products | Search and download geospatial data products |
/datasets | List available dataset categories |
| Dataset ID | Tag | Description |
|---|---|---|
| elevation-products-three-dep | National Elevation Dataset (NED) | 3DEP DEM tiles (1/3, 1, 2 arc-second) |
| elevation-source-data-lidar-isfar | National Elevation Dataset (NED) | Lidar and IfSAR source data |
| us-topo-main | US Topo | Current USGS topographic maps (GeoPDF) |
| historical-topographic-maps | Historical Topographic Maps | Historical 7.5-minute and 15-minute quads |
| hydrography-nhdplushr-nhd-wbd-main | 3D Hydrography Program (3DHP) | NHD flowlines, waterbodies, WBD watersheds |
| imagery-naip-plus | USDA NAIP | 1m to 0.5ft aerial imagery |
| national-boundary-dataset | National Boundary Dataset (NBD) | State, county, congressional district boundaries |
| names-geographic-names-information-system | GNIS | Geographic place names |
| structures-national-structures-dataset | NSD | Schools, hospitals, fire stations, etc. |
| transportation | NTD | Roads, railroads, trails |
| Parameter | Description | Example |
|---|---|---|
datasets | Dataset name (from list above) | National Elevation Dataset (NED) 1/3 arc-second |
bbox | Bounding box (minLon,minLat,maxLon,maxLat) | -80.5,39.5,-79.5,40.0 |
polygon | WKT polygon for spatial filter | (URL-encoded WKT) |
q | Text search across product metadata | Monongalia |
prodFormats | File format filter | GeoTIFF |
max | Maximum results to return | 10 |
offset | Pagination offset | 0 |
outputFormat | Response format | JSON (default) |
dateType | Date filter type | dateCreated or lastUpdated |
start | Start date for date filter | 2020-01-01 |
end | End date for date filter | 2024-12-31 |
| User asks about... | Dataset | Strategy |
|---|---|---|
| Elevation/DEM near a well | elevation-products-three-dep | Bounding box query around coordinates |
| Topographic map of an area | us-topo-main | Bounding box or text search by location name |
| Historical topo map | historical-topographic-maps | Text search + date filter |
| Lidar point cloud data | elevation-source-data-lidar-isfar | Bounding box query |
| Aerial imagery | imagery-naip-plus | Bounding box query |
| Streams/rivers near a site | hydrography-nhdplushr-nhd-wbd-main | Bounding box query |
| Geologic map | NGMDB MapView or SGMC WMS | Web map or WMS GetMap |
| Slope/terrain analysis | elevation-products-three-dep | Download DEM, analyze with GIS tools |
Search for elevation data (DEM) near a well site:
# 1/3 arc-second DEM tiles covering north-central WV
curl -s "https://tnmaccess.nationalmap.gov/api/v1/products?datasets=National+Elevation+Dataset+(NED)+1/3+arc-second&bbox=-80.5,39.5,-79.5,40.0&max=5" \
| jq '.items[] | {title, format, sizeInBytes, downloadURL}'
Search for USGS topographic maps:
# Current US Topo maps for an area
curl -s "https://tnmaccess.nationalmap.gov/api/v1/products?datasets=US+Topo&bbox=-80.1,39.6,-79.9,39.7&max=5" \
| jq '.items[] | {title, format, downloadURL}'
Search for historical topographic maps:
# Historical 7.5-minute quads
curl -s "https://tnmaccess.nationalmap.gov/api/v1/products?datasets=Historical+Topographic+Maps&bbox=-80.1,39.6,-79.9,39.7&max=5" \
| jq '.items[] | {title, publicationDate, downloadURL}'
Search for lidar data:
# Lidar source data for an area
curl -s "https://tnmaccess.nationalmap.gov/api/v1/products?datasets=Lidar+Point+Cloud+(LPC)&bbox=-80.1,39.6,-79.9,39.7&max=5" \
| jq '.items[] | {title, format, sizeInBytes, downloadURL}'
Search for NAIP aerial imagery:
# NAIP orthoimagery
curl -s "https://tnmaccess.nationalmap.gov/api/v1/products?datasets=USDA+National+Agriculture+Imagery+Program+(NAIP)&bbox=-80.1,39.6,-79.9,39.7&max=5" \
| jq '.items[] | {title, publicationDate, downloadURL}'
Search for hydrography data:
# NHD flowlines and watershed boundaries
curl -s "https://tnmaccess.nationalmap.gov/api/v1/products?datasets=National+Hydrography+Dataset+(NHD)+Best+Resolution&bbox=-80.5,39.5,-79.5,40.0&max=5" \
| jq '.items[] | {title, format, downloadURL}'
NGMDB MapView (web interface):
Navigate to https://ngmdb.usgs.gov/mapview/ and zoom to the area of interest. The MapView application overlays published geologic maps at various scales.
SGMC WMS (programmatic for geologic map tiles):
# USGS State Geologic Map Compilation WMS GetMap request
# Returns a geologic map image for a bounding box
curl -s "https://mrdata.usgs.gov/services/sgmc?service=WMS&version=1.1.1&request=GetMap&layers=sgmc&bbox=-80.5,39.5,-79.5,40.0&width=800&height=600&srs=EPSG:4326&format=image/png" \
-o /tmp/geologic_map_wv.png
# SGMC WMS GetFeatureInfo -- identify geologic unit at a point
curl -s "https://mrdata.usgs.gov/services/sgmc?service=WMS&version=1.1.1&request=GetFeatureInfo&layers=sgmc&query_layers=sgmc&info_format=text/plain&x=400&y=300&width=800&height=600&bbox=-80.5,39.5,-79.5,40.0&srs=EPSG:4326"
TNM API response structure:
{
"total": 18,
"items": [
{
"title": "USGS 1/3 Arc Second n40w080 20210111",
"sourceId": "60678639d34edc0435c0a5e6",
"metaUrl": "https://www.sciencebase.gov/catalog/item/60678639d34edc0435c0a5e6",
"publicationDate": "2021-01-11",
"lastUpdated": "2021-11-30",
"sizeInBytes": 468401044,
"extent": "1 x 1 degree",
"format": "GeoTIFF",
"downloadURL": "https://prd-tnm.s3.amazonaws.com/StagedProducts/Elevation/13/TIFF/...",
"boundingBox": {"minX": -80.0, "maxX": -79.0, "minY": 39.0, "maxY": 40.0}
}
],
"messages": ["Retrieved 18 item(s) Retrieved (1 through 5)"]
}
Format: Product Listing Table + Download Links + Narrative
## Elevation Data: North-Central West Virginia (39.5N-40.0N, 79.5W-80.5W)
**Dataset:** 3DEP 1/3 Arc Second (~10 meter resolution)
**Total tiles:** 18
**Showing:** 5 most recent
| Title | Date | Size (MB) | Format | Resolution |
|-------|------|-----------|--------|------------|
| USGS 1/3 Arc Second n40w080 20210630 | 2021-11-16 | 444 | GeoTIFF | ~10 m |
| USGS 1/3 Arc Second n40w080 20210111 | 2021-01-11 | 447 | GeoTIFF | ~10 m |
| USGS 1/3 Arc Second n40w081 20201015 | 2020-10-15 | 435 | GeoTIFF | ~10 m |
**Download (most recent):**